(a) Field of the Invention
The present invention is related to an electric machinery provided with a PM magnetic pole wrapped by conduction winding excited magnetic poles, and more particularly, to one that has a PM magnetic pole wrapped in the mid section of the magnetic circuit from an individual magnetic pole excited by conduction winding, or between an individual magnetic pole and a magnetic circuit, or between two individual magnetic circuits with different polarities of an individual magnetic pole excited by conduction winding and another individual magnetic pole excited by conduction winding of different polarities mounted in various types of electric machinery of the prior art.
(b) Description of the Prior Art
A magnetic polar structure to produce EME operation is mounted in a conventional DC or AC revolving or linear electric machinery, whether it is of commutator brush, brushless, ring brush, synchronous, asynchronous, internal revolving, external revolving, revolving with the electric magnetic structure at middle, double-acting, triple-acting, multi-layer, multi-ring, linear, DC brushless, or inverter electric machinery, or an electric machinery functioning as a generator or as a motor or as both a generator and a motor, coupling transmission device, as an EME vortex coupling transmission device, or an EME vortex braking device.
The magnetic pole structure of the prior art is comprised of:                PM magnetic pole structure;        DC or AC conduction winding excited individual magnetic pole structure; and         A conduction winding excited individual magnetic pole having on its pole-face disposed with an accumulative or differential excitement PM magnetic pole.        
As illustrated in FIG. 1 of the accompanying drawings for a schematic view showing a structure of an accumulative or differential excitement PM magnetic pole disposed on a pole-face of a conventional conduction winding excited individual magnetic pole, a PM magnetic pole 103 of accumulative excitement is disposed on a surface of a conduction winding 100 excited magnetic pole 101. The structure as illustrated in FIG. 1 provides advantage of reduction of excitement current but it is found with a flaw that the PM magnetic pole is vulnerable to falling off due to vibration or that magnetic force is weakened due to inverse excitation when the electric machinery is running; and the same flaw is also found with the structure of the PM magnetic pole.